diff options
| author | Lin Ming <ming.m.lin@intel.com> | 2012-04-23 09:03:49 +0800 |
|---|---|---|
| committer | Len Brown <len.brown@intel.com> | 2012-05-05 01:19:52 -0400 |
| commit | 1cc0c998fdf2cb665d625fb565a0d6db5c81c639 (patch) | |
| tree | 2768315b4d2217ea16082947bf995edfc40d5faf /drivers/acpi/scan.c | |
| parent | ec612fcf43e09f5e05d37baf4d3f138b3fcc2f3d (diff) | |
ACPI: Fix D3hot v D3cold confusion
Before this patch, ACPI_STATE_D3 incorrectly referenced D3hot
in some places, but D3cold in other places.
After this patch, ACPI_STATE_D3 always means ACPI_STATE_D3_COLD;
and all references to D3hot use ACPI_STATE_D3_HOT.
ACPI's _PR3 method is used to enter both D3hot and D3cold states.
What distinguishes D3hot from D3cold is the presence _PR3
(Power Resources for D3hot) If these resources are all ON,
then the state is D3hot. If _PR3 is not present,
or all _PR0 resources for the devices are OFF,
then the state is D3cold.
This patch applies after Linux-3.4-rc1.
A future syntax cleanup may remove ACPI_STATE_D3
to emphasize that it always means ACPI_STATE_D3_COLD.
Signed-off-by: Lin Ming <ming.m.lin@intel.com>
Acked-by: Rafael J. Wysocki <rjw@sisk.pl>
Reviewed-by: Aaron Lu <aaron.lu@amd.com>
Signed-off-by: Len Brown <len.brown@intel.com>
Diffstat (limited to 'drivers/acpi/scan.c')
| -rw-r--r-- | drivers/acpi/scan.c | 17 |
1 files changed, 7 insertions, 10 deletions
diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c index 767e2dcb961..7417267e88f 100644 --- a/drivers/acpi/scan.c +++ b/drivers/acpi/scan.c @@ -869,7 +869,7 @@ static int acpi_bus_get_power_flags(struct acpi_device *device) /* * Enumerate supported power management states */ - for (i = ACPI_STATE_D0; i <= ACPI_STATE_D3; i++) { + for (i = ACPI_STATE_D0; i <= ACPI_STATE_D3_HOT; i++) { struct acpi_device_power_state *ps = &device->power.states[i]; char object_name[5] = { '_', 'P', 'R', '0' + i, '\0' }; @@ -884,21 +884,18 @@ static int acpi_bus_get_power_flags(struct acpi_device *device) acpi_bus_add_power_resource(ps->resources.handles[j]); } - /* The exist of _PR3 indicates D3Cold support */ - if (i == ACPI_STATE_D3) { - status = acpi_get_handle(device->handle, object_name, &handle); - if (ACPI_SUCCESS(status)) - device->power.states[ACPI_STATE_D3_COLD].flags.valid = 1; - } - /* Evaluate "_PSx" to see if we can do explicit sets */ object_name[2] = 'S'; status = acpi_get_handle(device->handle, object_name, &handle); if (ACPI_SUCCESS(status)) ps->flags.explicit_set = 1; - /* State is valid if we have some power control */ - if (ps->resources.count || ps->flags.explicit_set) + /* + * State is valid if there are means to put the device into it. + * D3hot is only valid if _PR3 present. + */ + if (ps->resources.count || + (ps->flags.explicit_set && i < ACPI_STATE_D3_HOT)) ps->flags.valid = 1; ps->power = -1; /* Unknown - driver assigned */ |